An electronic device includes one or more substrates such as a printed circuit board (PCB) on which various components are mounted. The components mounted on the PCB perform various functions according to the purpose of the electronic device. The components need to be electrically interconnected to supply current required for the operation of each component and to exchange signals between the components. In order to electrically interconnect the components, solder paste is printed on the substrate, the components are mounted on the solder paste, and a pad portion formed on the substrate and the lead of the component are connected to each other.
Thus, for proper operation of the electronic device, it is necessary for the components mounted on the substrate to be correctly arranged and for the electrical connection therebetween to be desirably realized. However, due to various causes in the assembly process, the arrangement and electrical connection of the components may not be completely performed. For example, the electrical connection may not be performed, or may be insufficiently performed due to the solder paste being insufficiently applied. On the other hand, the solder paste may be applied in excess, resulting in an electrical short between adjacent pad portions or leads.
In order to solve the above problems, a three-dimensional substrate inspection technique for inspecting mounted states of substrate components using a three-dimensional image obtained by irradiating an object to be measured with patterned light and photographing the object to be measured which is irradiated with the patterned light has been introduced and utilized. For example, Korean Patent Publication No. 10-2007-0122014 discloses a three-dimensional substrate measurement apparatus using the patterned light.
A substrate inspection apparatus may include a display unit for displaying an image of a measured substrate so that a user is capable of confirming a substrate to be inspected. The user may inspect the mounted state of each of the components mounted on the substrate from the image of the substrate to be inspected displayed on the display unit.